Noise figure improvement of a double-pass erbium-doped fiber amplifier by using a HiBi fiber loop mirror as ASE rejecter

In this paper, the noise figure improvement of an erbium-doped fiber amplifier with double-pass configuration is demonstrated. By utilizing a high birefringence fiber loop mirror as the amplified spontaneous emission rejecter, the noise figure of this erbium-doped fiber amplifier (EDFA) greatly decreases compared with that of the EDFA using a conventional 3 dB fiber loop mirror. Moreover, stability observation of the amplifier output spectra ensures its applicability for practical applications.